Which term best describes sediment that is deposited in horizontal layers over time?

The term that best describes sediment that is deposited in horizontal layers over time is superposition. This principle is fundamental in geology and sedimentology, as it asserts that in undisturbed sedimentary sequences, the oldest layers will be found at the bottom, with progressively younger layers stacked above them. This layering occurs due to sediment being deposited by processes like water or wind action in a relatively stable environment, leading to the formation of horizontal beds of sediment.

Superposition is significant because it allows geologists to understand the geological history of an area by relating the position of sediment layers to their relative ages. This method provides insight into the sequence of geological events, the timing of sediment deposition, and the environmental conditions that prevailed at the time.

In contrast, erosion refers to the process of wearing away rock or sediment by wind, water, or ice, and does not focus on layering. Compaction relates to the process where sediment grains are packed closely together under pressure, which is a consequence rather than a description of the arrangement of sediments. Deformation indicates changes in the shape or structure of rocks due to various forces, which can disrupt the originally horizontal layering of sediment. Thus, the main focus of superposition on the chronological stacking of layers makes it the most appropriate term